Regulators estimate that the four bank failures will cost the insurance fund $80.8 million.

The FDIC lined up other lenders to assume the deposits and some of the assets of each bank.

Waccamaw Bank was the biggest. It had 16 branches and about $533.1 million in assets and $472.7 million in deposits, as of March 31. First Community Bank in Bluefield, Va., agreed to assume Waccamaw's deposits and buy about $515.3 million of the failed bank's assets.

The FDIC also entered a loss-share transaction with First Community Bank on $330.6 million of Waccamaw Bank's assets.

Farmers and Traders State Bank had two branches and roughly $43.1 million in assets and $42.3 million in deposits as of the end of March. First State Bank of Mendota, Ill., assumed all of Farmers and Traders' deposits and agreed to buy essentially all of its assets.

Carolina Federal Savings Bank had about $54.4 million in assets and $53.1 million in deposits. Bank of North Carolina in Thomasville, N.C., agreed to assume all of the failed bank's deposits to buy about $41 million of its assets.

First Capital Bank had about $46.1 million in assets and $44.8 million in deposits as of March 31.

F&M Bank in Edmond, Okla., agreed to pay a premium of about 7.7 percent to assume all of First Capital's deposits. It also agreed to buy about $40.7 million of the failed bank's assets.

The pace of bank closures has slowed sharply after ballooning as the financial crisis took hold in 2008. By this time last year, 45 banks had failed.

In 2010, regulators seized 157 banks, the most in any year since the savings and loan crisis two decades ago. Those failures cost the deposit insurance fund around $23 billion. The FDIC has said 2010 likely was the high-water mark for bank failures from the Great Recession. Last year's 92 failures cost an estimated $7.9 billion.

In 2009, there were 140 bank failures that cost the insurance fund about $36 billion, more than it paid out the following year because the banks involved in 2009 were bigger on average. Twenty-five banks failed in 2008, the year the financial crisis struck with force; only three were closed in 2007.

From 2008 through 2011, bank failures cost the fund an estimated $88 billion. The FDIC expects failures from 2012 through 2016 to cost $12 billion.

The deposit insurance fund fell into the red in 2009. With failures slowing, the FDIC's fund balance turned positive in the second quarter of last year.

By Dec. 31, it stood at $11.8 billion, about 50 percent higher than three months earlier, according to the FDIC.